Plastic bituminous insulating composition



Patented Nov. 2, 1943 UNITED PLASTIC BITUMINOUS INSULATING COMPOSITIONOrville V. McGrew. Chicago, Ill.

No Drawing. Application July 22, 1940, Serial No. 346,863

9 Claims. (01.106-278) This invention relates to a plastic bituminousinsulating composition adaptable for use upon building and otherstructures, and particularly adapted to be sprayed on such structures inthick layers which will not crawl, slide, or slip even after applicationto vertical or sloping structures, which can be applied cold, and whichwill dry rapidly.

In one modification the plastic composition includes a large amount ofcork which improves the heat insulating qualities of the material, andthis aspect of the invention is covered specifically in my co-pendingapplication Serial No. 264,492, filed March 27, 1939.

Bituminous products are well known for many purposes and are availablein a variety of forms. There are certain classes of bituminous materialswhich must be applied hot, these containing very little solvent andsetting rapidly to form a coating material. These hot materials,however, do not have the characteristics necessary for application tocertain types of work, particularly to housing structures or the like.

Bituminous materials are also available which employ aqueous emulsionsof asphalt as the base, but, these, in order to be applied properly to avertical surface without running, must be loaded heavily with pigmentsand furthermore do not resist weathering due to the fact that theasphalt emulsions are not totally non-reversible. Therefore, there is atendency for water to re-emulsify or to penetrate the asphalt and causedestruction by freezing or otherwise.

Cut-back asphalts are also known. These materials consist of abituminous base, which is dissolved in a volatile hydrocarbon solventsuch as ent invention deals with cut-back asphalts. In

applying a cut-back asphalt to a vertical structure by spraying, it isnecessary that the product, once applied, shall not run on application,and shall not slide or crawl after application, shall dry rapidly eventhough in thick layers, and shall produce, after application, awaterproof, weatherproof, insulating surface. In order to develop amaterial capable of forming such a surface, the bituminous materialitself must be carefully selected, the ratio of solvent to asphaltcarefully controlled, and more important, the proportion of filler toasphalt and solvent must be carefully regulated.

In my co-pending application, Serial No. 264,492, is described acut-back asphalt insulatin: composition suitable to application tovertical wall structures in thick layers, which embodies a fillerpredominantly of cork. The cork of course varies in density to a certainextent, but the variation in density between the various types of corkis relatively small compared to the difference between the density ofcork and other fillers.

I have now discovered that other fillers may be substituted for cork inthe formulas of my foregoing application, provided due allowance is madefor the density of the fillers. The present invention includes a formulaby which not only the usual fillers such as clay, zinc oxide, litharge,powdered limestone, slate dust or flour, kieselguhr, tripoli, and otherinert materials of usual density, but very light. and very heavy fillerssuch as vermiculite, granulated rubber, or rubber grindings, and otherrubber products; sawdust, barium sulfate and others may be suitablyemployed.

The determination of the true density of a filler is quite a diflicultproblem. For example, mica is an excellent filler. Mica in mineral formhas a specific gravity of 2.6 to 3.2 but commercially it is used in veryfinely divided form and has a weight as low as 2.5 lbs. per gallon, or aspecific gravity of approximately 0.3. In the present case the termdensity is used to indicate the 'efiective volume which the particularfiller occupies in the liquid or solid, as the case may be. It will behereinafter explained how this density may be calculated.

The following are examples of products prepared in accordance with thisinvention:

Example I The figures hereinafter given are based upon a 100 lbs. batch.

31.9 lbs. of an oleum glue base are prepared using approximately ofbituminous material and 40% of a petroleum solvent having an initialboiling point of 315 R, an end point of 375 F., a flash point of F., anda specific gravity at 60 F. of 53 to 55 B. This product has a meltingpoint of approximately 200 F. before addition of the solvent and apenetration at 77 F. of 12 mm. The Mid-Continent asphalt employed inthis product is a mixture of Oklahoma base and Arkansas base flux oilswhich have been air blown to raise their melting point to about FL,after which about 33% of gilsonite is added. While a melting point ofabout 200 F. and a penetration of about 12 mm. is preferred, there is nosubstantial variation over a to be handled in manufacturing but requiresadditional thinning for application.

With it are mixed 23.2 lbs. of a light glue base which is composed ofMid-Continent asphalt having a melting point of approximately 145 F.-and a penetration of 48 mm. at 77. This is cut back with petroleumsolvent having an initial boiling point of 370 R, an end point of 500'.F., a flash point of 135 F., and a specific gravity at 60 F. of 40 to42 B. The solvent is employed in an amount of approximately 35% to 40%of the light glue base, variations being to take account of localclimatic conditions. Similarly, the ratio of oleum glue base to lightglue base" may be altered, more of the oleum glue base being used inwarm climates than in cold.

Filler is then added to the composition in sufficient amount to give itthe proper body for weather resistance, flow resistance, and fireresistance. A suitable proportion is 18.4 pounds of Kankakee clay havinga density Of 6.48 lbs. per gallon; 9.7 lbs. of asbestos floats having aweight of 3.07 lbs. per gallon; 3.5 lbs. of N0. 160 mica having a weightof 2.71 lbs. per gallon; and 0.2 lb. of cork'dust having a weight of1.40 lbs. per gallon. j

Additional solvent and thinner is then added to the mixture to give itthe proper viscosity, but ordinarily the control point is 60 to 70seconds Stormer viscosity. In the above example this was obtained byadding 5.4 lbs. of engine distillate weighing 6.9 lbs. per gallon; and7.7 lbs. of oleum spiri having a weight of 6.4 lbs. per gallon.

Oleum spiritsis a trade designation for a petroleum distillate fractionbetween naphtha and kerosene, having a flash point of approximately 100F.; a B. gravity of approximately 54 to 56; an initial boiling point ofapproximately 310 F.; and an end point of approximately 390- Enginedistillate is a trade designation for a petroleum distillate or spiritapproximating No. 1 fuel oil and about the first cut above kerosene. Theproduct has a B. gravity of approximately 38 to 40; an initial boilingpoint of approximately from the apparent density thereof in the form'used. Since the asphalt and solvent are in effect liquids, the fillerwill by subtraction be seen to occupy only 1.37 gallons of space. Thespecific gravityof the material in the wet form is 1.15. Upon' drying, afurther shrinkage occurs, the apparent density of the materialincreasing to 1.35 and the apparent volume occupied being reduced toapproximately 5.76 gallons. The weight of the material reduces to about64.86 lbs, The original weight per gallon is 9.35 lbs. and in. dry formis 11.255 lbs.

Of the final volume of 5.76 gallons, approximately 3.89 gallons is takenup by the asphalt, leaving a difference "of 1.87 gallons of whichapproximately 1.37 gallons is occupied by 31.3 lbs. of filler. Thedifference between these figures, or .50 gallon is assumed to representvoids in the material. The true density of the filler is, therefore,2.78, which represents 26% of the total true volume of the dry material.(5.26 gallons). The proportion in the liquid is 5 or 12.8%. Theremaining constituents represent 74% in the solid and 87.2% in theliquid.

The liquid had a specific gravity of 1.15 and the solid of 1.35(uncorrected). The filler factors are determined as follows:

L 2 Dry filler factor- X D where A is the percentage by volume trulyoccupied by the filler (determined as already indicated), B is thepercentage of the volume truly occupied by the remaining constituents, Cis the true specific gravity of the filler as it exists in the product,and D is the true density of the product after allowing for voidsdetermined as indicated.

In the above formula, substitution of the results for Example I givesthe following equation:

For determining the liquid filler factor, the formula is:

Wet filler factor= In general the factor for the dry material will bebetween 0.60 and 1.00, and preferably between 0.65 and 0.85. For theliquid, the factor should be between 0.20 and 0.50, but preferablybetween approximately 0.25 and 0.45. Variations within this formula areshown in the following examples:

- Example II A siding material was prepared according to the followingformula:

Pounds Ingredients Gallons 33. 2 4.3 19. 4 59 6. 5 94 5. 0 Oleum spirits92 20. 3 K ee clay--. 3. 12 11. 2 Asbestos floats 3. 66 3.3 No.160mica1.24 2 Cork dnsf 14 The actual yield from the above formula is 10.75gallons, having a specific gravity of 1.12. The liquids occupied 8.88gallons of this, leaving 1.87 gallons actually occupied by the filler.

The product yielded, on drying, 6 gallons of material weighing 66.56lbs. and having an apparent specific gravity of 1.33. Of this product,3.71 gallons was asphalt weighing 31.56 lbs. The remainder, or 1.87gallons, was occupied by the filler which wei hed 35 lbs. Its truespecific gravity was, therefore, 2.25. It occupied 33.5% of the truevolume of the solid material and 17.4% by volume of the liquid.

In the above formula "oleum glue base and light glue base" are made upin the same manner as hereinbefore described.

The true volume of the dry product being 5.58 gallons, its true specificgravity was 1.43. The dry filler factor was, therefore,

The wet filler factor was,

Example III This example relates to one similar to those set Y forth inmy aforesaid co-pending application,

Serial No. 264,492. This material is prepared according to the followingtable:

The actual yield of the above material was 16.2 gallons for 100 lbs.

With this material, as in the previous examples, the solvent and thinnerwill preferably be a material having a minimum flash of 100 F. and aninitial boiling point of 315 F., an end point of 375 F. and a specificgravity of 53 to 55.". On the other hand, if the material is used wherethere is no danger of fire, V. M. 8: P. solvent with lower flash andboiling points may be employed. or course other volatile solvents may besubstituted, but, in any event, the viscosity of the material must beadjusted to a proper spraying consistency.

The above cork mixture had an initial density of 0.74. With the abovematerial the actual density of the resulting dry product will varyconsiderably, depending upon the manner of application and the surfaceto which the material is applied. This is due to the fact that, upondrying, there is a considerable proportion of voids in the mass. Inpractice, the apparentspecific gravity will vary from 0.42 to 0.54.

Since the liquid content of the fluid amounts to 11.23 gallons, thefiller occupies a true volume of 4.97 gallons and thus has a truedensity of 0.42, since it weighs 17.5 lbs.

The volume of the dry material will vary from 10.9 to about 13.1gallons, of which 8.7 gallons will actually represent the total volumeof the filler and the asphalt, and the rest will represent air spacesacting as insulating chambers within the-product. The apparent densityof the dry material is from 0.42 to 0.54 but its true density, basedupon a volume of 8.7 gallons for 48.9 lbs. of material, is 0.677. Thefiller occupies 57.1% of the solid, and 31% of the liquid. The dryfiller factor is, therefore:

It will be observed that Example III has a dry mula. This is due to thefact that the filler is lighter than the volatile solvent and,therefore, the density of the material decreases rather than increasesupon evaporation of the solvent. It is, therefore, preferred, whencomparing a material which has a filler heavier than the solvent to onewhich has a filler lighter than the solvent, to use a more complicatedformula in which D and H are both replaced by the average of D and H. Inother words, the dry filler factor equals:

and the wet filler factor equals:

Using a modified formula, the following filler factors are obtained forthe three examples just given.

Dry filler Wet filler factor factor Using this more accurate formula,the dry filler factor should be between 0.60 and 1.00 and preferablybetween 0.70 and 0.90. The wet filler factor should be between 0.20 and0.45 and preferably between 0.24 and 0.38.

The composition set forth in Example III had an extremely highinsulating value, having a K factor of 0.42 or lower. The specificcomposition set forth in the composition had a K factor of 0.39. Slightmodifications of the formula, however, for example by using more corkdust, will give a product having a much higher K factor.

Therefore, even though the larger cork particles give rise to seriousproblems in spraying, it is preferred to use them in order to producehigh insulating value.

This application is a continuation-in-part of my co-pending application,Serial No. 264,492, filed March 27, 1939, which was acontinuationin-part of Serial No. 144,558, filed May 24, 1937, which wasa division of Serial No. 115,254, filed December 10, 1936, which "hasnow issued as Patent 2,145,027 dated January 24, 1939.

The foregoing detailed description is given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom.

What I claim as new, and desire to secure by Letters Patent, is:

1. A plastic bituminous insulating composition comprising a normallysolid bituminous base, a volatile solvent for-the bituminous base, and afiller, the ratio of solvent and filler to base being such as to producea thick tacky sprayable composition suitable for application even tovertical structures in layers at least V8 inch in thickness withoutrunning, sliding, or slipping after application, and capable of dryinguniformly throughout when so applied, and said material having a wetfiller factor of between 0.20 and 0.45 inclusive, determined accordingto the following formula:

E Wet filler factor- X where E is the percentage by volume occupied bythe filler in the liquid, F is the percentage by volume of the remainingconstituents of the liquid, C is the true specific gravity of thefiller, and H is the specific gravity of the liquid as prepared forapplication.

2. A product as set forth in claim 1, in which the wet filler factor isbetween 0.25 and 0.45

where E is the percentage by volume occupied by the filler in theliquid, F is the percentage by volume of the remaining constituents ofthe liquid, is the true specific gravity of the filler, and H is thespecific gravity of the liquid as prepared for application; said producthaving the property of producing a dry flame-proof, insulating, adherentcomposition with high weathering characteristics, and having a dryfiller factor of approximately 0.60 to 1.00, determined according to thefollowing formula:

Dry filler factor=%X% where A is the percentage byvolume'truly occupiedby the filler in the dry product, B is the percentage of volume trulyoccupied by the remaining .constituentsof the dry product, 0 is the truespecific gravity of the filler as it exists in the product, and D is thetrue specific gravity of the dried product.

4. A product as set forth in claim 3, in which the dry filler factor ofthe dried, product is from 0.65 to 0.85.

5. A plastic bituminous insulating material comprising a normally solidbituminous base, a volatile solvent forthe bituminous base, and afiller, theratio of solvent and filler to base being such as to producea thick tackysprayable compositionsuitable for application even tovertical structures in layers at least 54; inch in thickness withoutrunning, sliding, or slipping after application, and capable of dryinguniformly throughout, when so applied, and said producthaving a wetfiller factor between 0.20 and 0.45, as det r mined by the followingformula:

Wet filler factor- -X m pared for application, and D is the truespecific gravity of the product after drying; said product having theproperty of producing a dry flameproof, insulating, adherent compositionwith high weathering characteristics, and having a dry filler factor ofapproximately 0.70 to 1.00, determined according to the followingformula:

where A is the percentage by volume truly occupied by the filler in thedry product, B is the percentage of volume truly occupied by theremaining constituents of the dry product, C is the true specificgravity of the filler as it exists in the product, D is the truespecific gravity of the Dry filler factor=%X dried product, and H is thespecific gravity of the liquid as prepared for application.

6. A product as set forth in claim 5, in which the dry filler factor isfrom 0.70 to 0.90 and the wet filler factor is from 0.25 to 0.35.

7. A composition as set forth in claim 1, in which the filler includes asubstantial proportion of'cork.

'8. A plastic bituminous insulating material capable of drying invertical sheets to a waterproof, weather-proof, flame resisting,insulating composition, comprising a normally solid bituminous base, avolatile solvent for the bituminous base, and a filler, the ratio ofsolvent and filler to base being such as to produce a thick tackysprayable composition suitable for application to vertical structures inlayers at least /8 inch in thickness without running, sliding, orslipping after application-,- said material having a wet filler factorof between 0.20 and 0.45, inclusive, determined according to thefollowing formula:

E 20 Wet filler factor where E is the percentage by volume occupied bythe filler in the liquid, F is the. percentage by volume of theremaining constituents of the liquid, C is the true specific gravity ofthe filler, H is the specific gravity of the liquid as prepared forapplication, andD is the true specific gravity of the product afterdrying.

9. A product as set forth in claim 8, in which the product is preparedby mixing approximately 31.9 lbs. of an oleum glue base includingapproximately 60% asphalt having a. melting point I of approximately 200F. and 40% of petroleum where E is the percentage by volume occupied bythe filler in the liquid, F is the percentage byvolume of the remainingconstituents of the liquid, C is the true specific gravity ,of thefiller, H is the specific gravity of the liquid as presolvent having aspecific gravity at 60 F. of approximately 54 B., with approximately23.2 lbs. of a light glue base composed of asphalt having a meltingpoint of approximately F. cut back with a petroleum solvent having aspecific gravity at 60 F. of approximately 41 B., the solvent beingapproximately 35 to 40% of the'light glue base, and a filler comprisingessentially clay, asbestos, and mica; together with thinner.

ORVILLE V. McGREW.

